The invention relates to a forming station for chip or fiber panel.
In the production of chip or fiber panels, flowable or free-flowing materials such as chips or fibers provided with a binder agents are discharged out of a dosing or metering hopper and delivered to a spreading head as a spreading apparatus, by means of a forming station. Through the spreading head, the chips or fibers are spread to form a fleece or mat onto a continuously running forming belt, and are then formed to a finished panel in a subsequent pressing station.
Such a forming station is previously known from the company prospectus xe2x80x9cForming Stationxe2x80x9d, SP 0208, issued March 1985, by the company Carl Schenck AG in Darmstadt. Therein, the glued chip or fiber material is discharged out of the dosing or metering hopper over the entire width by means of discharge rolls, and is transported to a spreading head, in order to then be spread onto a forming belt. Spreading rolls of a certain width are generally arranged in the known spreading heads, whereby these spreading rolls distribute the chip or fiber fleece or mat to a certain width onto the forming belt. In practice, it is often necessary, however, to spread panels with varying widths on the same spreading station. Therefore, very often, the largest possible width of the fleece or mat is spread onto the forming belt, and then the excessively wide portion is uniformly removed on each side from the forming belt. The excess fleece material is then transported back into the dosing hopper via conveyor apparatus. Since the returned panel material is already provided with a binder agent, physical and/or chemical changes arise during the return transport, which disadvantageously influence the final quality of the panels.
A forming station with a spreading head is previously known from the DE GM 71 37 773, in which the width of the fleece to be spread-out is adjustable in the spreading head. For this purpose, slidable guide parts and adjustable side walls are provided below a return wiper rake in the spreading head, by means of which the spreading width can be reduced in a certain range. In this context, the guide parts are arranged vertically between a wiper rake and a dosing or metering belt and can be moved sideways toward one another or away from one another. Thereby, a pre-fleece or pre-mat can be formed on the dosing belt, whereby the width of this pre-fleece is adjustable by the sliding displacement of the guide parts. Thereby, the height of the pre-fleece is prescribed by the height of the guide parts. This pre-fleece is then dissolved or broken-up by a spreading roll and spread to a chip fleece on a forming belt arranged thereunder, whereby the spreading width is adapted to the width of the pre-fleece by means of adjustable side walls. Since the hopper walls are not also adjustable in connection with a belt width adjustment, first the dosing hopper must be emptied, before further spreading can be carried out with a smaller spreading width. Thereby it necessarily leads to a stopping or standstill of the forming station, which means an interruption of production.
It is therefore the object of the invention to provide a spreading station of which the spreading width is adjustable without production interruption and material return transport.
This object is achieved by the invention in a forming station comprising: a spreading apparatus, a forming belt, a dosing hopper out of which is transport flow of flowable materials including chip and fiber-form materials is delivered in a transport direction to the spreading apparatus, through which a material fleece of the flowable materials is spreadable onto the forming belt, and a compartmentalized chute arranged vertically and longitudinally in the transport flow between the dosing hopper and the forming belt, wherein the compartmentalized chute comprises plural guide plates which are arranged next to one another in the transport direction and are all respectively spaced apart from one another by spacing distances in a transverse direction that extends transversely relative to a longitudinal conveying direction of the forming belt, so as to form a respective compartment channel between each two adjacent ones of the guide plates, thereby dividing the transport flow in the transport direction into plural side-by-side partial flows respectively in the respective compartment channels. Further details and advantageous example embodiments are recited in the dependent claims.
The invention has the advantage, that basically any desired spreading widths can be adjusted by means of a simple varying of the spacing distances of the guide plates or sheets relative to each other. Thereby, in a simple manner, it is also possible to achieve an adaptation to differing widths of dosing hoppers, conveyor apparatus, spreading heads, and forming belts. Such a spreading width adjustment can advantageously also already be provided after the dosing hopper, so that the prescribed spreading width is already supplied to the following conveyor apparatus or the spreading head. Hereby, in a simple manner, the uniformity of the spreading can be improved, because the material flow is already supplyable to the spreading apparatus in the width that is to be spread-out.
The invention further has the advantage, by means of the adjustability of several adjacently located partial streams, that the material accumulation at the panel edges is reducible to a minimum by means of the division or distribution among several partial streams. In this manner, through simple measures, a material accumulation on the outer side edges is avoidable, which simultaneously leads to a uniform spreading.
A particular embodiment of the invention has the advantage that a very planar, even and uniform spreading of the chips or the fiber fleece is achieved by means of an inclined or sloping arrangement of the guide sheets or plates relative to the transport direction, because the accumulations overlap with the depressions directly under the guide plates due to the inclined arrangement. Hereby especially in the context of the spreading of fiber panels, it is advantageously usually no longer necessary to provide a subsequent height-adjustable equalizing roller. In a particular manner of embodying the invention, in which the compartmentalized chute is width-adjustable, the inclined positioning of the guide plates is achievable in an advantageous manner in that the compartmentalized chute is adjusted, for example, to be narrower or wider in the rear than in the front.
A further particular embodiment of the invention had the advantage that basically any desired spreading widths are adjustably settable by means of an automatic varying of the spacing distances of all of the guide plates relative to each other or entire groups of guide plates. Thereby, the spreading of a different panel width can be carried out, even during the operation, without production interruptions. The particular embodiment of the invention further has the advantage that a durable, problem-free adjusting operation is possible for many years by the mechanical adjusting means and the lever-like coupling, even though the most difficult environmental conditions prevail during the panel production due to considerable burdens of dust, heat and chemicals. Thereby, it is especially advantageous, by means of the lever-like coupling of the guide plates, all of the guide plates or groups of guide plates are adjustable by constant or differing adjustment distances in their total width, through a simple linear movement of a few lever arms.